It's been almost 3 weeks since my daughter started her nursing strike. Does anyone have any solution for this?

Ebm as in expressed bm? Have you considered changing the teat of the bottle? If there's no significant change to your diet that affects the taste of your bm, perhaps there has been certain changes on ur child's diet or even schedule? At 7.5months she would have started solids, is she over fed on solids? Try adjusting the quantity or the meal time and also the bottle, maybe a sippy cup or straw cup?